Flexible tying member for theftproof device

ABSTRACT

A flexible tying member for a theftproof device which is adapted to give warning in response to a change in a photo signal transmitted in an optical fiber extending through the flexible tying member. The flexible tying member has a first layer including the optical fiber and at least one electric wire connected to at least one photoelectric element, and a second layer including a reinforcing member. The flexible tying member has a coaxial structure having an inner layer formed by the above first layer, and an outer layer formed by the above second layer, or a parallel structure in which the above first and second layers longitudinally extend parallel with each other.

BACKGROUND OF THE INVENTION

This invention relates to a theftproof device, and more particularly toa flexible tying member forming part of a theftproof device and throughwhich an optical fiber extends.

A theftproof device for vehicles such as motorcycles has been proposedby the assignee of the present application, which uses a flexible tyingmember such as a wire cable, through which an optical fiber extends. Theproposed theftproof device is used in such a manner that a vehicle,which is to be protected from theft, is tied to a solid structure suchas an electric pole, by means of the above flexible tying member, whilea photo signal is permanently transmitted through the optical fiber.When the flexible tying member is cut in two to cause interruption ofthe transmission of the photo signal through the optical fiber, thecutting of the flexible tying member is detected in a photoelectricmanner to actuate a warning device to give warning.

Such flexible tying member with an optical fiber incorporated thereinshould desirably have sufficient strength so as to withstand frequentuse. Further, it should have a simple structure such that it can bemanufactured at moderately low costs.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to provide a flexible tying member fortheftproof devices, which has an optical fiber extending therethrough,and which has sufficient strength, and has a simple structure enough topermit manufacturing at low costs.

A theftproof device, to which the present invention is applicable,comprises an elongate flexible tying member, an optical fiberlongitudinally extending through the flexible tying member, a pair ofphotoelectric elements arranged at opposite ends of the optical fiber,and means responsive to a change in an electric signal generated by oneof the photoelectric elements, which corresponds to a change in a photosignal generated by the other photoelectric element and transmitted inthe optical fiber, for performing a warning function. The elongateflexible tying member comprises a first layer including the opticalfiber and at least one electric wire longitudinally extending throughthe tying member and electrically connected to at least one of the abovephotoelectric elements, and a second layer including a reinforcingmember longitudinally extending through the tying member.

In a preferred form, the flexible tying member has a coaxial structurein which the first layer is arranged at the diametric center of thetying member and extending along the axis of same, and the second layeris concentrically disposed around the first layer. In another preferredform, the flexible tying member has a parallel structure in which thefirst and second layers are longitudinally fitted through a flexiblehollow tubular member in a manner extending parallel with each other.

The above and other objects, features and advantages of the inventionwill be more apparent form the ensuing detailed description taken inconnection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an example of an electrical circuitfor use in a theftproof device to which the flexible tying memberaccording to the present invention is applicable;

FIG. 2 is a schematic view illustrating, by way of example, a manner ofusing a theftproof device to which the flexible tying member of thepresent invention is applied;

FIG. 3 is a schematic side view of a motorcycle on which the main bodyof the theftproof device appearing in FIG. 2 is mounted;

FIG. 4 is a cross-sectional view illustrating the flexible tying memberaccording to an embodiment of the present invention;

FIG. 5 is a fragmentary side and broken view illustrating the flexibletying member of FIG. 4;

FIG. 6 is a cross-sectional view illustrating the flexible tying memberaccording to a further embodiment of the invention;

FIG. 7 is a fragmentary side and broken view illustrating the flexibletying member of FIG. 6;

FIG. 8 is a cross-sectional view illustrating the flexible tying memberaccording to a still further embodiment of the invention;

FIG. 9 is a fragmentary side and broken view illustrating the flexibletying member of FIG. 8; and

FIG. 10 is a fragmentary side and broken view illustrating amodification of the flexible tying member of FIGS. 8 and 9.

DETAILED DESCRIPTION

The flexible tying member according to the present invention will now bedescribed in detail with reference to the drawings which illustrateseveral embodiments thereof. In the drawings, like reference charactersdesignate like or corresponding parts throughout all the views.

Referring first to FIG. 1, there is illustrated an electrical circuit,by way of example, for use in a theftproof device to which the flexibletying member of the present invention is applicable. In FIG. 1,reference numeral 1 designates a light emission element 1 as aphotoelectric element, such as a light emission diode, which is arrangedat one end of an optical fiber 21 longitudinally extending through aflexible tying member 2 which is preferably formed of a wire cable, asherienlater described in detail. A light receiving element 3 as anotherphotoelectric element, such as a phototransistor, is arranged at theother end of the optical fiber 21. The light emission element 1 and thelight receiving element 3 are electrically connected to an electricalcircuit 4. The electrical circuit 4 is adapted to supply an electricsignal to the light emission element 1 and generate a warning signal incooperation with a warning device 5 connected to the output of theformer, in response to an output of the light receiving element 3. Apower source 6 is connected to the electrical circuit 4 and the warningdevice 5 to supply them with electric power. In the illustrated example,the light receiving element 3 and the electrical circuit 4 are connectedtogether by way of lead wires 22 and 22' which are windingly disposed inthe flexible tying member 2 of the inventon, as hereinlater described.

The electrical circuit 4 comprises a generator circuit 4a a receivercircuit 4b, a fiber-cutting detecting circuit 4c, and a driving circuit4d. The generator circuit 3a can be formed by a pulse generator, whichis adapted to generate an electric pulse signal Pa having apredetermined constant pulse repetition period. The light emissionelement 1, which is adapted to convert an electric signal into acorresponding photo signal, is operable in response to the pulse signalPa to generate a corresponding photo pulse signal Ph. This photo pulsesignal Ph is transmitted through the optical fiber 21. The lightreceiving element 3, which is adapted to convert a photo signal into acorresponding electric signal, is operable in response to the photopulse signal Ph inputted thereto through the optical fiber 21 togenerate a corresponding electric pulse signal Pb. The receiver circuit4b is arranged to receive and detect the signal Pb supplied thereto fromthe light receiving element 3 to generate a corresponding electric pulsesignal Pc. The fiber-cutting detecting circuit 4c is arranged to besupplied with the pulse signals Pa and Pc, respectively, from thegenerator circuit 4a and the receiver circuit 4b for detection ofdisconnection or cutting of the optical fiber 21, depending upon theinput signals. For instance, it can be adapted to determine fulfillmentof an "AND" condition of the levels of the signals Pa and Pc to generatean abnormality-indicative signal Pd when it determines that the ANDcondition is not fulfilled. The driving circuit 4d, which is adapted andarranged to actuate the warning device 5, is responsive to the inputsignal Pd to generate a driving signal Ps. The warning device 5, whichcan be formed of a buzzer, is responsive to the input driving signal Psto give an alarm.

FIG. 2 schematically illustrates a theftproof device to which theflexible tying member, the electrical circuit, etc. in FIG. 1 areapplied. The theftproof device has a casing 7 in which are accommodatedthe electrical circuit 4, the warning device 5 and the power source 6,all appearing in FIG. 1. The casing 7 is rigidly mounted on a vehicle,e.g. on a motorcycle, as shown in FIG. 3, at a predetermined location,for instance, at a side wall of a rear cowl 14 under a seat 13.

The flexible tying member 2 carries at its one end 2a a plug 8 securedthereon, in which are accommodated the light emission element 1 in FIG.1 and a connector, neither of which is shown in FIG. 2. The flexibletying member 2 also carries at its other end 2b a caulking metal holder10 rigidly secured on the same end in a caulked manner. The metal holder10 accommodates a capsule, not shown, in which the light receivingelement 3 in FIG. 1 is supportedly disposed in alignment with anassociated end of the optical fiber 21. The end 2b of the flexible tyingmember 2 and the capsule are held together by the metal holder 10, in amanner forming a loop 2c.

To tie a vehicle to an electric pole or the like by means of theflexible tying member of FIG. 2, the flexible tying member 2 is woundround an electric pole 9 or the like, then the plug 8 is passed throughthe loop 2c, and then the same plug is locked into a locking hole 11formed in the casing 7. In FIG. 2, reference numeral 12 designates alock for preventing disengagement of the plug 8 form the locking hole11.

Details of the flexible tying member 2 according to the invention, whichis used in the above manner, will now be described with reference toFIGS. 4 through 10. In the following embodiments, the flexible tyingmember 2 is formed of a wire cable as a most preferable material, andis, therefore, hereinafter called "the lock wire cable"

Referring first to FIGS. 4 and 5, there is illustrated a firstembodiment of the lock wire cable 2 of the invention. An optical fiber21, which is coated with a protective layer 23 formed of a syntheticresin such as polyvinyl chloride and polyethylene, is arranged at thediametric center of the lock wire cable 2, together with two lead wires22 and 22' as electric conductors. The optical fiber 2 and the leadwires 22 and 22' are longitudinally fitted through a flexible tube 24formed of a synthetic resin such as polyethylene, as a hollow tubularmember, in a manner extending parallel with each other, forming a firstlayer together with the tube 24. The first layer is thus arranged at thediametric center of the lock wrie cable 2 and longitudinally extendsalong the axis of same. Concentrically disposed or wound around the tube24 along its whole length are a plurality of, e.g. six strands 25, eachformed of a plurality of, e.g. seven twisted steel wires 26. Thesestrands 25 serve as a reinforcing member. The strands 25 are coated withanother protective layer 27 formed of a synthetic resin such aspolyvinyl chloride, as an outer wall member, which fills gaps betweenthe individual strands 25. A second layer is thus formed by the strands25 and the protective layer 27.

As noted above, the optical fiber 21 is arranged at the diametric centerof the lock wire cable 2 in a manner enclosed by the tube 24, thestrands 25, etc. so that it is fully protected from being damaged oreasily cut due to external disturbances. Further, the optical fiber 21extends along the axis of the lock wire cable 2 in a streamline mannerwithout any unnecessary curved portion, and accordingly can transmitlight or a photo pulse signal Ph in FIG. 1 through a minimum possibledistance from an end to the opposite end. In the other words, the totallength of the optical fiber 21 can be reduced to keep the transmissionloss of light transmitted therethrough at a very small value. Also,having no tortuous or curved portion, the optical fiber 21 can havesufficient light transmission efficiency, i.e. a large lighttransmission amount per unit length.

Although in the arrangement of FIGS. 4 and 5, the optical fiber 21 andthe lead wires 22 and 22' longitudinally extend parallel with eachother, they may be twisted together with a large pitch, according tonecessity.

FIGS. 6 and 7 illustrate a second embodiment of the lock wire cable ofthe invention. An optical fiber 21, which is coated with a protectivelayer 23 formed of a material similar to the one in the firstembodiment, is arranged at the diametric center of the lock wire cable2, together with two lead wires or electric conductors 22 and 22',similar to the ones in the first embodiment. The optical fiber 21 andthe lead wires 22 and 22' are twisted together with a large pitch. Theoptical fiber 21 and the lead wires 22 and 22' are coated with asynthetic resin material 24' such as polyvinyl chloride as a coatingmaterial to form an integral core as a first layer together with thelatter. The first layer is thus arranged at the diametric center of thelock wire cable 2 and longitudinally extends along the axis of same.Concentrically disposed or wound around the above core or first layeralong its whole length are a plurality of, e.g. six strands 25, eachformed of a plurality of, e.g. seven twisted steel wires 26, similar tothe ones in the first embodiment. The strands 25 are coated with aprotective layer 27 formed of a synthetic resin similar to the one inthe first embodiment, as an outer wall member, which also fills gapsbetween the individual strands 25, exactly, radially outer peripheralsurfaces of same, forming a second layer together with the latter.

The strands 25 are wound onto the above core or first layer when thesynthetic resin material 24' is still in a state softened by heat, thatis, before it sets up. Therefore, the synthetic resin material 24'completely fills gaps between the strands 25, the optical fiber 21, andthe lead wires 22 and 22', and accordingly the outer peripheral surfaceof the core or first layer has a shape or profile corresponding to thatof the inner peripheral surfaces of the strands 25. The lead wires 22and 22' are each coated with an insulating material 31 formed ofpolyvinyl chloride, polyethylene, or the like and having a relativelylarge thickness to avoid shorting between the lead wires and the strands25.

The use of the synthetic resin material 24' makes it possible to fullyutilize spaces between the optical fiber 21, the lead wires 22 and 22'and the strands 25 in a manner completely filling the gaps therebetween,which permits reducing the outer diameter of the lock wire cable 2.Further, the optical fiber 21 and the lead wires 22 and 22' are fullyprotected from being damaged or easily cut due to external disturbances,enabling the lock wire cable to withstand frequent use. In addition,ends of the lead wires 22 and 22' can be easily taken out from therespective ends of the lock wire cable 2, facilitating wiring operationfor electrical connection of the ends of the lead wires with associatedconnectors.

Althrough in the embodiment in FIGS. 6 and 7, the optical fiber 21 andthe lead wires 22 and 22' are twisted together with a large pitch, theymay be disposed in the wire to extend substantially parallel with eachother.

FIGS. 8 and 9 illustrate a still further embodiment of the lock wirecable 2 of the invention. According to this embodiment, a first layer isformed by an optical fiber 21 coated with a synthetic resin layer 23similar to the one in the first embodiment, and two lead wires orelectric conductors 22 and 22' extending parallel with the optical fiber21. This first layer is longitudinally fitted through a flexible tube27' as another hollow tubular member, which is formed of synthetic resinsuch as polyvinyl chloride, together with a reinforcing member 28forming a second layer, in a manner extending parallel with thereinforcing member 28. The reinforcing member 28 is formed by a core 29formed of a string of hemp yarn or the like, disposed along the axis ofthe member 28, a plurality of, e.g. six strands 25, each formed of aplurality of, e.g. six twisted steel wires 26, wound around the core 29,and an outer wall layer 30 formed of a synthetic resin such as polyvinylchloride, coating the strands 25. The lead wires 22 and 22' are eachcoated with an insulating material 31 similar to the one in the secondembodiment.

Since the optical fiber 21, the lead wires 22 and 22', and thereinforcing member 28 are all longitudinally fitted through the flexibletube 27' together in a manner extending parallel with each other, thelock wire cable 2 is simple in structure, and can therefore bemanufactured with ease and at low costs. Further, the longitudinalarrangement of the optical fiber 21 in the flexible tube 27' along withthe reinforcing member 28, etc. can make it possible to reduce the totaleffective length of the optical fiber 21 to keep the transmission lossof light therethrough at a very small value, and also to preventtortuosity of the optical fiber 21 which can cause a reduction in thelight transmission efficiency.

Although in the embodiment of FIGS. 8 and 9, the optical fiber 21, thelead wires 22 and 22', and the reinforcing member 28 extend parallelwith each other, they may alternatively be twisted together with a verylarge pitch, as shown in FIG. 10.

According to any of the embodiments described above, which all use areinforcing member disposed along the optical fiber, the lock wire cablehas sufficient strength, and is simple in structure. Therefore, it canbe manufactured with ease and at low costs.

Moreover, the lead wires 22 and 22' are not limited in number to two asin the illustrated embodiments, but only a single such lead wire may beused, as a positive conductor, for instance, and in such a case, thestrands 25 formed of steel wires may be arranged to conduct electriccurrent therein, for use as one of the electric conductors, as anegative conductor, for instance.

The structure of the wire cable as the reinforcing member is notlimitative, but many modifications and alterations are possible inrespect of the numbers of the strands 25 and the twisted steel wires 26and the manner of twisting them. Alternatively, the wire cable may beformed by a plurality of wire ropes twisted together. That is, thestructure and size of the wire cable may be selected from a wide varietyof structures and sizes, depending upon the required outer diameter,strength, etc. of th lock wire cable 2.

What is claimed is:
 1. An elongate flexible tying member having anoptical fiber longitudinally extending through said flexible tyingmember and a pair of photoelectric elements arranged at opposite ends ofsaid optical fiber, for use in a theftproof device including meansresponsive to a change in an electrical signal generated by one of saidphotoelectric elements, which corresponds to a change in a photo signalgenerated by the other of said photoelectric elements and transmitted insaid optical fiber, for performing a warning function, said flexibletying member further comprising:a first layer including said opticalfiber and at least one electric wire which longitudinally extendsthrough said flexible tying member and is electrically connected to atleast one of said photoelectric elements, said optical fiber and atleast one electric wire being arranged around the axis of the tyingmember, said first layer being disposed at a diametric center of saidflexible tying member and extending along an axis thereof, said firstlayer including a coating material coating said optical fiber and saidat least one electric wire; and a second layer including a reinforcingmember wound around said first layer and longitudinally extendingthrough said flexible tying member, said reinforcing member of saidsecond layer comprising a plurality of strands, each strand comprising aplurality of twisted steel wires, said second layer being coaxiallyarranged around an outer peripheral portion of said first layer andsubstantially in contact with the first layer; said coating materialfilling gaps between said optical fiber, said at least one electricwire, and said reinforcing member.
 2. The flexible tying member asclaimed in claim 1 wherein said second layer has at least an outerperipheral portion thereof formed by a synthetic resin material.
 3. Theflexible tying member as claimed in claim 1 wherein said optical fiberand said at least one electric wire of said first layer longitudinallyextend parallel with each other.
 4. The flexible tying member as claimedin claim 1 wherein said optical fiber and said at least one electricwire of said first layer are twisted together.
 5. The flexible tyingmember as claimed in claim 1 wherein said reinforcing member is formedof an electrically conductive material, and electrically connected toone of said photoelectric elements to also serve as another one of saidat least one electric wire.
 6. An elongate flexible tying member havingan optical fiber longitudinally extending through said flexible tyingmember and a pair of photoelectric elements arranged at opposite ends ofsaid optical fiber, for use in a theftproof device including warningmeans responsive to a change in an electrical signal generated by one ofsaid photoelectric elements, which corresponds to a change in a photosignal generated by the other of said photoelectric elements andtransmitted in said optical fiber, for performing a warning function,one of said photoelectric elements comprising a light source and theother of said photoelectric elements comprising a light receptor, saidflexible tying member further comprising:a loop formed at one end ofsaid flexible tying member; connection means at the other end of saidflexible tying member for detachably connecting said other end to awarning means; a first layer including said optical fiber and twoelectric wires which longitudinally extend through said flexible tyingmember from said connection means, said first layer being disposed at adiametric center of said flexible tying member and extending along anaxis thereof, said optical fiber and electric wires being arrangedaround the axis of the tying member, said electric wires beingelectrically connected to the one of said photoelectric elements at saidone end of said flexible tying means adjacent said loop, said firstlayer including a coating material coating said optical fiber and saidelectric wires; and a second layer including a reinforcing member woundaround said first layer and longitudinally extending through saidflexible tying member, said reinforcing member of said second layercomprising a plurality of strands, each strand comprising a plurality oftwisted steel wires, said second layer being coaxially arranged aroundan outer peripheral portion of said first layer and substantially incontact with the first layer; said coating material filling gaps betweensaid optical fiber, said at least one electric wire, and saidreinforcing member.